Page 103 - The Ontario Curriculum, Grades 9 and 10: Science, 2008 (revised)

periodic table. A graphic arrangement of chem- ical elements into rows and columns, devised by Dmitri Mendeleev in the nineteenth century, based on patterns of similar properties.
pH scale. A numerical scale ranging from 0 to 14 used to classify aqueous solutions as acidic, basic, or neutral. Acidic solutions have a pH less than 7. Basic solutions have a pH greater than 7. Neutral solutions have a pH equal to 7.
phloem. Specialized plant tissue used for carry- ing sugars and amino acids.
phosphorescence. A light that is emitted while the source is exposed to electromagnetic radia- tion, and that continues after the excitation source has been removed.
photosynthesis. The process by which green plants, algae, and certain bacteria make energy for themselves by using the energy from sun- light plus water to convert carbon dioxide into carbohydrates. The process produces oxygen as a byproduct. Photosynthesis produces the oxygen and carbohydrates that all animals need to survive.
physical properties. Qualities or attributes of matter that do not involve chemical change.
plane mirror. A mirror with a flat reflective surface. polyatomic ion. A charged particle containing more than one atom.
potential difference. The difference in electric charge between two points that will cause cur- rent to flow in a closed circuit.
precipitate. A solid, insoluble product of a chem- ical reaction found in a liquid.
product. The new substance formed during a chemical reaction.
property. An attribute common to all substances or objects of the same group.
proton. The dense, positively charged particle found in the nucleus of an atom.
pure substance. A substance made of only one kind of material and having uniform properties throughout.
qualitative data. Information describing the characteristics or properties of the objects or substances being observed.
quantitative data. Information concerning the amounts or measurements of the objects or sub- stances being observed.
reactant. A material that starts a chemical reaction.
reflection. The changing of direction of a light ray caused by bouncing it off a surface. All ob- jects reflect light to some extent, some (such as a mirror) better than others. Sound can also be re- flected; a common example of this is an echo.
refraction. The bending of light as it travels from a material with one refractive index to a material with a different refractive index.
renewable energy sources. Energy sources that can be replenished by natural processes in a rela- tively short period of time (e.g., energy from the sun, wind, tide, waves, biomass).
resistance. The degree to which a substance op- poses the flow of an electric current through it.
retrograde motion. The movement of an object in the sky, usually a planet, from east to west, rather than in its normal motion from west to east. This effect is generally produced when Earth is passing the planet in its orbit.
salinity. The amount of dissolved salt in water.
satellite. A celestial body orbiting another of larger size; or a human-made object or vehicle orbiting the earth, the moon, or other celestial bodies.
scientific inquiry. The cognitive strategy and hands-on procedures through which students develop knowledge and understanding of scien- tific ideas and of the various methods scientists use to study the natural world.
GLOSSARY
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